Pressure-responsive anchor for well packing apparatus



Feb. 21, 1967 M.YP. LEBOURG 3,305,021

PRESSURE-RESPONSIVE ANCHOR FOR WELL PACKING APPARATUS Filed June 11, 1964 6 Sheets-Sheet 1 MOO/V66 P. 1 eourg INVENTOR.

* A WM M. P. LEBOURG Feb. 21,1967

PRESSURE-RESPONSIVE ANCHOR FOR WELL PACKING APPARATUS Filed June 11, 1964 6 Sheets-Sheet 2 4 9 5 07% Z w W H fwm M m m m .%A P 6 C W M m Filed June 11, 1964 1967 M. P. LEBOURG 3,305,021

. PRESSURE-RESPONSIVE ANCHOR FOR WELL PACKING APPARATUS 6 Sheets-Sheet 4 Maur/re leau/y INVENTOR ATTOR/Vfy Feb. 21, 1967 M. P. LEBOURG PRESSURE-RESPONSIVE ANCHOR FOR WELL PACKING APPARATUS Filed June 11, 1964 6 Sheets-Sheet 5 MGUf/( 1 Zeou/y INVENTOR.

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ATTORA/L'V Feb. 21, 1967 M. P. LEBOURG PRESSURE-RESPONSIVE ANCHOR FOR WELL PACKING APPARATUS Filed June 11, 1964 6 Sheets-Sheet 6 1L1 7 4 k 7 y a, MVJJJ m a a w y m 5 a m Z J W E M m 2 w 6 ,h a 6, ,6, w

INVENTOR.

United States Patent This invention relates to packer or plugs for packingoff a well bore; and, more particularly, to packers or plugs which, when set in place, will be anchored against hydraulic pressure in the well acting on the plug or packer from either direction by an anchoring force proportionately related to the acting pressure.

In conducting such well-completion operations as acidizing, cementing, or fracturing, a full-opening well packer dependently coupled from a tubing string is positioned at a particular depth in a cased well and the packer set to isolate the formation interval to be treated from the remainder of the well bore thereabove. Treating fluids are then pumped downwardly at high pressure through the tubing and packer and introduced into the formation being treated through perforations appropriately located in the casing. In those instances where a well having several producing formations is being completed, a selectively operable retrievable bridge plug can be dependently coupled beneath the full-opening packer. Such a bridge plug permits pack-off zones of selected length in the well bore for selective treatment of different formation intervals with only one trip in the well.

It will be appreciated that such packers and bridge plugs must be capable of withstanding high pressures acting from either direction. Furthermore, during the course of typical completion operations, both types of such packing apparatus can be subjected to high pressures acting alternately from both above and below the apparatus. Accordingly, it is necessary to securely anchor such packing apparatus against movement in either longitudinal direction.

Heretofore, extendible slip members have typically been employed to anchor packing apparatus from movement in at least one direction. Extendi-ble anchoring members have also been developed which are hydraulically actuated by the fluid being pumped'through the tubing and secure the apparatus against shifting.

Retrievable bridge plug in the past have generally employed cup-type packers which, have particular limitations in that the cups (1) sometimes become defective while in service within a well bore, (2) they are not capable of eifective sealing where a low pressure differential exists and can break down with high pressures that are sometimes present in a well bore, and (3) a fluid bypass must be provided through the tool body.

Accordingly, it is an object of the present invention to provide new and improved packing apparatus having hydraulically actuated wall-engaging members which are pressed into anchoring engagement with a force proportionately related to the pressure of the fluid in the well.

It is an additional object of the present invention to provide new and improved retrievable bridge plugs which employ expandable and retractable elastomeric annular packing elements rather than cup-type packers.

It is a further object of the present invention to provide new and improved well packing apparatus which is capable of being releasably anchored in a packed-off condi- "ice tion and resist extreme forces and pressure differentials from either longitudinal direction.

It is still another object of the present invention to provide retrievable 'bridge plugs having annular packing elements which are expanded into sealing engagement by rotative motion of an actuator.

Packing apparatus arranged in accordance with the present invention includes selectively operable wall-engaging means operated by a self-contained hydraulic system which, in response to the pressure of fluids in a well, is adapted to press the wall-engaging means into anchoring engagement with a force proportionately related to this fluid pressure. After the packing element and wall-engaging means are selectively extended, the hydraulic system responds to a pressure difierential across the apparatus to maintain the apparatus anchored against the casing with an anchoring force which is proportional to this pressure differential.

The novel features of the present invention are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation together with further objects and advantages thereof, may 'best be understood by way of illustration and example of certain embodiments when taken in conjunction with the accompanying drawings in which:

FIG. 1 is a view of a full-bore packer and a bridge plug employing principles of the present invention and depicted as they would appear within a well bore;

FIGS. 2A-2E are detailed cross-sectional views in succession of an embodiment of a bridge plug;

FIG. 3 is an isometric view showing particular details of a locking groove employed with the bridge plug of FIG. 2;

FIG. 4 is an isometric view showing particular details of a friction anchor employed with the present invention;

FIG. 5 is a cross-sectional view taken along the line 55 of FIG. 2C;

FIG. 6 is a view showing the upper end of the bridge plug of FIG. 2 with its equalizing valve open;

FIG. 7 is a view similar .to FIG. 6, but with the equalizing valve closed;

FIG. 8 is a partial View of an alternate embodiment of a bridge plug;

FIG. 9 is a partial view of another alternate embodiment of a bridge plug;

FIG. 10 is a cross-sectional view taken along the line 10-10 of FIG. 9.

As seen in FIG. 1, a typical full-bore packer 20 with a conventional hold-down (not shown) on its mandrel is dependently connected from a tubing string 21 and positioned within a well bore 22 having a casing 23 set therein. A retrievable bridge plug 24 is shown sealingly and anchoringly engaged with the casing 23. An overshot 25 dependently connected beneath the well packer 20 is releasably coupled to a fishing neck 26 on the bridge plug 24. This releasable coupling allows the bridge plug 24 to be set at the lower limit of a particular formation interval and the packer 20 subsequently set at any point thereabove irrespective of the length of the tubing sub 27 connecting the packer to the bridge plug.

Turning now to FIGS. 2A-2E, the retrievable bridge plug 24 depicted in FIG. 1 is constructed in accordance with the principles of the present invention and includes a rotatable tubular sleeve member 28 (FIG. 2B) having one end telescopically arranged within and threadedly engaged with a tubular housing member 29 (FIGS. 2B-

2E). Elastomeric packing means 30 (FIG. 2B) mounted around the tubular sleeve 28 are arranged to be foreshortened and expanded outwardly into sealing engagement whenever the tubular sleeve 28 is rotated in one direction relative to the housing 29. Rotation of the tubular sleeve 28 in the opposite direction will, of course, allow the elastomeric packing means 30 to relax and return to their normal position.

An actuating body member or index mandrel 31 (FIGS. 2A-2E) is slidably engaged and co-rotatively secured within the tubular sleeve 28 and extended on into the housing 29. Normally engaged latch means 32 (FIG. 2C) releasably latch the mandrel to the housing 29 to prevent the mandrel 31 from shifting longitudinally until the mandrel has first been rotated a predetermined amount as it screws the tubular sleeve 28 inwardly into the housing to foreshorten the packing means 30. The members 28, 29 and 31 are, of course, made in separate sections which are arranged with threaded connections where needed to facilitate manufacture and assembly. These threaded connections are not shown, however, for purposes of greater clarity.

The housing 29 is initially restrained against rotation by a set of conventional spring-biased drag blocks 33 (FIG. 2B) mounted around the housing and arranged to be continuously biased outwardly against the casing. As is customary, the force exerted by these blocks is not sufficient to prevent the bridge plug 24 from being longitudinally shifted through the casing. Once the bridge plug 24 has been brought to rest, however, the static frictional drag imposed by the drag blocks 33 will be suflicient to effectively hold the housing 29 fixed as the index mandrel 31 is rotated therein.

A hydraulically-actuated, radially-expansible, friction anchor 34 (FIGS. 2C-2D) mounted on the housing 29 is adapted to be pressed against the casing whenever the mandrel 31 shifts longitudinally 'in either direction with respect to the housing to anchor the bridge plug 24 relative to the casing.

The lower end of the rotatable tubular sleeve member 28 is threadedly engaged and received within particularly arranged right-hand threads 35 (FIGS. 2B-2C) around the upper end 36 of the housing 29. The sleeve member 28 is provided with a series of inwardly projecting, longitudinal splines 37 (FIG. 2B) spaced around its inner bore 38 which are cooperatively and slidably received within a series of substantially elongated, complementary, longitudinal spline grooves 39 formed around the periphery of the index mandrel 31. As will be subsequently described, once the latch means 32 (FIG. 2C) has been released from the mandrel, these splines 37 and their longer mating grooves 39 allow the mandrel 31 to freely shift longitudinally with respect to the sleeve member 28 but prevent these members 28, 31 from rotating relative to one another.

The elastomeric packing means 31) (FIG. 2B) are mounted around the tubular sleeve 28 and disposed between the upper end 36 of the housing and a downwardly facing annular shoulder 40 provided around the upper end of the sleeve. A tubular guard 41 loosely disposed around the tubular sleeve 28 and inside of the packing means 30 allows the sleeve to rotate freely within the packing element. Thus, as the tubular sleeve 28 is being screwed downwardly into the housing 29 to foreshorten the packing means 30, no torque is applied against the internal circumferential surfaces of the packing means. For similar reasons, a freely swiveling annular ring 42 around the upper end of the packing means 30 allows the sleeve 28 to rotate without twisting the upper end of the packing means.

The releasable latching means 32 (FIG. 2C) normally holds the index mandrel 31 fixed longitudinally with respect to the housing 29, but is so arranged that it is selectively released by torquing the mandrel 31 in a clockwise direction as the packing means 30 is being foreshortened. The latching means 32 is comprised of a reciprocable lug member 43 which is slidably received within an inwardly directed lateral bore or recess 44 provided in a central portion of the housing 29. A spring member 45 biases the log 43 inwardly so that its inner end 46 is engaged within a T-shaped groove 47 in the periphery of the mandrel 31 whenever this groove is in juxtaposition with the end of the lug.

As shown in detail in FIG. 3, the T-shaped groove 47 has a fiat bottom 48 out along a plane including a chord of the circular cross-section of the mandrel 31'. The groove 47 has an elongated portion 49 extending longitudinally along the mandrel 31 and a branch portion 50 extending to the right and perpendicularly away from the center of the longitudinal groove portion 49. As shown isometrically in FIG. 3, the elongated groove portion 49 provides a continuous shoulder 51 along its left side, opposed semicircular shoulders 52, 53 at each end, and short shoulders 54, 55 along its right side on opposite sides of the branch portion 50. The branch portion 50 diverges as it extends away from the elongated groove portion 49 with the fiat bottom 48 being terminated and slightly rounded-off where it intersects and merges into the outer surface of the mandrel 31.

It will be understood that so long as the inner end 46 of the spring-loaded lug 43 is within the longitudinal groove portion 49, the mandrel 31 can shift only a very limited distance longitudinally. Left-hand rotation of the index mandrel 31 relative to the housing 29 is, of course, prevented by the end 46 of the lug 43 engaging the straight shoulder 51 of the longitudinal slot portion 49. Moreover, as the bridge plug 24 is being raised or lowered within the casing, it will be appreciated that the end 46 of the lug 43 will be respectively shifted into the positions 56, 57 shown by dashed lines in FIG. 3. Thus, so long as there is either an upward or downward force on the mandrel 31, shoulder 54 or shoulder 55 will prevent the mandrel from being rotated to the right as well. The mandrel 31, therefore, must first be shifted in such a manner that the lug end 46 is substantially in a neutral position 58 before 'it can be torqued to the right for setting of the bridge plug 24.

Accordingly, when the lug end 46 is placed in the neutral position 58, clockwise rotation of the index mandrel 31 will rotate the fiat surface 48 from under the lug end to gradually urge the spring-loaded lug 43 back into its recess 44. Continued rotation of the mandrel 31 in this direction will, of course, depress the spring-loaded lug 43 and free the mandrel 31 as the packing means 30 is being set. Once the spring-loaded lug 43 is disengaged from the T-groove 47, the index mandrel 31 is then free to shift longitudinally relative to the housing 29 as well as to the sleeve member 28.

Mounted around the housing 29 is an expansible anchor assembly 34 (FIGS. 2C-2D) with parts thereof being shown in detail in FIGS. 5 and 6. This assembly 34 includes an elastomeric sleeve 59 encircling the housing 29 with a plurality of elongated casing-contacting members 60, 61 uniformly mounted around the periphery of the sleeve. The upper 62 and lower 63 ends of the clastomeric sleeve 58 are enlarged and sealingly secured within peripheral recesses 64, 65 provided in the housing 29.

Each of the casing-engaging members 60, 61 are elongated and have a thick, arcuate cross-section (FIGS. 4 and 5). Alternate ones of these casing-engaging members are centrally aligned and mounted along the outer convex surface of relatively thin, elongated, arcuate backing members 66. A suflicient number of these mounted members 60 are disposed uniformly around the periphery of the elastomeric sleeve 59 so that the backing members 66 substantially encompass the sleeve. The remaining unmounted casing-engaging members 61 are alternately disposed between the mounted casing-engaging members 60 in such a manner that the unmounted members 61 will 5. straddle adjacent backing members 66 and cover the gap 67 therebetween.

The ends of the casing-engaging members 60, 61 are beveled, as at 68, for reception within opposed annular recesses 64, 65 around the housing 29 at opposite ends of the members (FIGS. 2C-2D). A longitudinal slot 69, 70 cut into each of the members 60, 61 receives one end of arcuate leaf springs 71, 72 which normally bias the casingengaging members radially inwardly. The opposite ends of these leaf springs 71, 72 are received within the annular housing recesses 64, 65 and engaged against inwardly directed shoulders 73, 74 formed therein. It will be appreciated that although the casing-engaging members 60, 61 are moved radially outwardly again-st springs 71, 72 whenever the elastomeric sleeve 59 is inflated, the beveled end portions 68 of the casing-engaging members will engage and be stopped by the inwardly directed shoulders 73, 74 of recesses 64, 65 in the housing at opposite ends of the members 60, 61.

Turning now to the hydraulic system of the present invention, the housing 29 is formed in such a manner as to provide an annular chamber 75 (FIG. 2C) above the upper end of the anchor 34 and a similar annular chamber 76 (FIG. 2D) below the lower end of the anchor. An annular clearance space 77 between the index mandrel 31 and housing 29 provides fluid communication from the upper chamber 75 to the lower chamber 76. A plurality of radial ports 78 through the housing 29 adjacent the elastomeric sleeve 59 provide fluid communication from this clearance space 77 into the sealed space underneath the elastomeric sleeve.

The upper end of the upper annular chamber 75 and the lower end of the lower annular chamber 76 are re spectively closed by annular piston members 79, 80 which are slidably mounted relative to both the housing 29 and the index mandrel 31. The upper slidable piston member 79 (FIG. 2C) is biased upwardly by a spring 81 which normally urges this piston member 79 against a downwardly directed shoulder 82 formed in the housing at the upper end of the upper chamber 75. Annular grooves around the outer and inner surfaces, respectively, of the upper piston member receive O-rings 83, 84 which fluidly seal the slidable piston member 79 relative to the housing 29 as well as to the index mandrel 31.

In a similar manner, the lower slidable piston member 80 (FIG. 2D) is biased downwardly by a spring 85 so that the lower piston member normally rests against an upwardly directed shoulder 86 formed in the housing 29 at the lower end of the lower chamber 76. Similarly, external and internal annular grooves around the piston member 80 receive O-rings 87, 88 to fluidly seal the slidable piston member 80 relative to both the housing 29 and the index mandrel 31.

. A shoulder 89 (FIG. 2C) located on the mandrel 31 a short distance above the upper slidable piston 79 is so arranged that whenever the mandrel 31 shifts downwardly, the shoulder will engage upper piston 79 and force the piston downwardly. Similarly, a second shoulder 90 (FIG. 2D) is provided on the mandrel to engage and shift lower piston member 80 upwardly whenever the mandrel 31 shifts in that direction.

It will be appreciated that with a suitable fluid in the above-described hydraulic system, longitudinal shifting of the mandrel 31 in either direction will expand the elastomeric sleeve 59 of the anchor 34 and press the casingengaging members 60, 61 against the casing. Thus, as the tubular sleeve 28 (FIG. 2B) is being rotated downwardly by the mandrel 31 to set the packing means 30, the upper piston 79 (FIG. 2C) Will be engaged and forced downwardly by the mandrel shoulder 89. Downward shifting of this piston 79 will, of course, cause the anchor 34 to be extended into anchoring engagement with the casing.

A compensating chamber 91 (FIGS. 2D-2E) is provided in the housing 29 beneath the lower piston member 6 to ensure that the hydraulic system remains full as' well as to compensate for thermal expansion of the hydraulic fluid. The lower end of this compensating chamber 91 is closed by a slidable annular compensating piston member 92 (FIG. 2B) having O-rings 93, 94 around its outer and inner surfaces, respectively, which fluidly seal the compensating piston relative to the housing 29 and mandrel 31. A relatively light spring 95 underneath the compensating piston holds it off of an annular spacer member 96 which, in turn, rests on an upwardly facing housing shoulder 97. The spring 95 will contract and expand in accordance with thermal expansion of the hydraulic fluid and continuously bias the compensating pis ton 92 against the hydraulic fluid.

Selectively controlled fluid communication is provided between the compensating chamber 91 and the remainder of the hydraulic system through an annular clearance space formed by a reduced-diameter portion 98 (FIG. 2D) around the index mandrel 31. ameter portion 98 is arranged to be in juxtaposition with the lower piston 80 whenever the mandrel 31 is in its previously described latched position. Whenever the mandrel 31 is shifted only a slight distance longitudinally, however, the inner sealing member 88 around the inner bore of lower piston member 80 fluidly seals the piston to the mandrel at either 99 or 100, depending upon the direction in which the mandrel shifts.

Turning now to the operation of the bridge plug 24, whenever the bridge plug has been positioned at the depth in the well bore where it is desired to set the packing element 30, the tubing string 21 is manipulated properly to shift the locking lug end 46 to its neutral position 58. The tubing 21 and index mandrel 31 are then rotated to the right. This rotation allows the bottom 48 of the T-shaped groove 47 to cam the locking lug 43 (FIG.

2C) back into its recess 44 thereby freeing the mandrel 31 from the housing 29. The housing 29 is, of course, secured against this rotation since the drag. blocks 33 hold the housing fixed relative to the casing. Accordingly, right-hand rotation of the mandrel 31 frees it from the housing 29 as it simultaneously (in view of splines 37 and grooves 39) begins to.screw the sleeve 28 downwardly into the housing along the threads 35 (FIG. 2B).

As the sleeve 28 is screwed downwardly, it will be appreciated that the downwardly facing shoulder 40 around the upper end of the sleeve advances toward the upper end 36 of the housing 29 to foreshorten the packing means 30. The pitch of the threads 35 is appropriately selected so that approximately only three-quarters of a revolution is required to advance the sleeve 28 a sufiicient distance to fully displace the packing means 30 into sealing engagement with the casing. An upwardly directed housing shoulder 101 (FIG. 2C) is arranged to be engaged by the lower end 102 (FIG. 2B) of the sleeve 28 and halt further advancement of the sleeve whenever it has rotated approximately three-quarters of a revolution which otherwise might allow the lug 43 to. snap back into the T-shaped groove 47 and relatch the mandrel.

It will be further appreciated that when the mandrel 31 moves downwardly only a slight distance with respect to the housing 29, the reduced-diameter portion 98 (FIG. 2D) of the mandrel is shifted out of juxtaposition with the lower slidable piston member 80. Whenthis reduced diameter portion 98 shifts a slight distance downwardly relative to the lower slidable piston member 80, O-ring 88 sealingly engages the periphery of the mandrel at 99 to trap all hydraulic fluid in the system above the lower slidable piston member. It will also be noted that continued downward travel of the mandrel 31 will soon bring the upper shoulder 89 (FIG. 2C) projecting outwardly from the mandrel into engagement with the upper piston member 79 and begin to shift it downwardly. Thus, with the lower piston 80 engaged against shoulder 86 and sealed at 99 around the mandrel 31, as shoulder 89 continues to advance the upper slidable pis- This reduced-diton member 79 downwardly in the housing 29 toward the lower piston 80, a hydraulic pressure is developed in the system. This developed hydraulic pressure expands the elastomeric sleeve 59 and extends the casing-engaging members 60, 61 (FIGS. 2C-2D) of the anchor 34 outwardly into tight engagement with the well casing. It will be understood, of course, that due to the relative in compressibility of hydraulic fluids, a considerable hydraulic pressure will be developed within the hydraulic system and, moreover, that this pressure will be imposed against the substantial surface area of the elastomeric sleeve member 59. Thus, the casing-engaging members 60, 61 will be pressed against the casing with a considerable force, which force will be sufiicient to anchor the bridge plug 24 against substantial longitudinal directed forces.

It will be appreciated, therefore, that after the bridge plug is set, should the pressure in the well bore above the bridge plug 24 be greater than the pressure below, the pressure differential will act on the effective cross-sectional area of the index mandrel 31 and shift the mandrel further downwardly. Downward shifting of the mandrel 31 accordingly drives the upper slidable piston member 79 further downwardly, which action will, of course, further increase the hydraulic .pressure within the system to press the casing-engaging members 60., 61 of the anchor 34 even more tightly against the well casing.

Should, perchance, the pressure in the well bore below the bridge plug 24 become greater than that thereabove, the mandrel 31 will similarly be shifted upwardly. As the mandrel 31 shifts upwardly, the upper slidable piston member 79 will, of course, be returned to its initial position against shoulder 82 by spring 81 and the hydraulic pressure will be momentarily reduced. As the mandrel 31 continues to travel upwardly, however, the lower slidable piston member 80 (FIG. 2D) is quickly rescaled by O-ring 88 around the mandrel 31, but now at 100 on the opposite side of reduced-diameter portion 98. The lower outwardly-extending upwardly-directed shoulder 90 on the mandrel will then engage the lower slidable piston member 80 and begin shifting it upwardly against spring 85. This upward movement will, of course, again increase the hydraulic pressure within the fluidfilled system to maintain the casing-engaging members 60, 61 tightly pressed against the well casing.

Accordingly, it will be appreciated that well pressure acting on the bridge plug 24 from either longitudinal direction will proportionately increase the hydraulic pressure which correspondingly forces the casing-engaging members 60, 61 even more tightly against the well casing. Furthermore, the bridge plug 24 will remain anohoringly engaged so long as the pressure seals in the hydraulic system remain effective.

It should be noted that once latching means 32 releases, the mandrel 31 is relatively free to shift longitudinally in either direction with respect to the tubular sleeve member 28 (FIG. 2B) in view of the difference in lengths of the splines 37 and the spline grooves 39. Thus, the mandrel can shift upwardly a considerable distance within the tubular sleeve 28 without imposing an upward force against the sleeve which might otherwise tend to rotate the sleeve upwardly along threads 35.

As seen in FIGS. 2A-2E, the mandrel 31 is provided with a central axial bore 103 which is selectively opened and closed by an equalizing valve 104 (FIG. 2A). Thus, whenever the bridge plug 24 is being traversed through a fluid-filled well bore, the equalizing valve 104 is left open to allow well fluids to also fiow freely through the mandrel bore 103 rather than all of the well fluid being forced through the confined annular space between the casing and retracted packing means 30. The housing 29 is terminated at its lower end with a junk pusher 165 (FIG. 2E) having ports 106 therein which allow well fluids to enter the central bore 103 of the index mandrel.

The equalizing valve 104 (FIG. 2A) is arranged to be selectively closed after the bridge plug 24 has been set into anchoring and sealing engagement with the well casing. Then, whenever the bridge plug 24 is to be released, the valve 104 is first reopened to equalize the well pressure across the bridge plug.

The fishing neck 26 is arranged for receiving the overshot 25 which may be dependently coupled to either the packer 20 or tubing string 21. Matched J-slots 107 on opposite sides of the fishing neck 26 receive cooperativelyarranged J-pins 108 on the overshot 25. When the overshot 25 is lowered over the fishing neck 26, the J-pins 108 will readily enter the open upper end of the J-slots 107. The pins are lockingly engaged in the lower end of the slots by a concerted application of left-hand torque and a slight upward pull on the tubing 21. Conversely, the overshot 25 is disengaged from the fishing neck 26 by lowering the tubing 21 slightly, torquing it to the right, and then pulling upwardly. A shoulder in the open portion of I-slots 107 will allow the bridge plug 24 to be set also by pulling up on the mandrel 31 while rotating to screw the sleeve 28 downwardly.

As seen in FIGS. 6 and 7, the fishing neck 26 closes off the upper end of the longitudinal bore 103 extending through the index mandrel 31. A group of lateral equalizing ports 109 are provided around the upper end of the mandrel 31 immediately below the fishing neck 26. Fluid communication through these ports 109 is selectively controlled by an annular valve member 110 which is slidably disposed around the mandrel 31 immediately below the equalizing ports. O-rings 111-114 are arranged around the inner surface of the valve member 110 and outer surface of the mandrel 31, respectively, to close the ports 109 Whenever the equalizing valve member 110 is shifted upwardly to its closed position (FIG. 7). This slidable member 110 is cooperatively arranged to be longitudinally shifted by particular manipulation of the running overshot 25 so that the equalizing ports 109 are uncovered whenever the overshot is engaged over the fishing neck 26 (FIG. 6) and covered whenever the overshot is removed (FIG. 7).

A shoulder 115 projecting inwardly from the central portion of the overshot 25 is arranged to engage the upper end of sliding valve member 110 and shift the valve member downwardly to its open position as the overshot is being coupled onto the fishing neck 26. Whenever the overshot 25 is removed by torquing it to the right and picking up, a group of resilient fingers 116 spaced around the lower portion of the overshot 25 are arranged with inwardly projected shoulders 117 to engage a shoulder 118 on the sliding valve member 110 and pull it upwardly to close the equalizing ports 109. A similar group of depending resilient fingers 119 around the lower end of the slidable valve member 110 are cooperatively arranged to be cammed outwardly as they pass over an annular shoulder 120 around the index mandrel 31 and then retracted after clearing the shoulder. Thus, the lower ends 121 of these fingers 119 will engage the upwardly facing portion of the annular shoulder 120 and hold the slidable valve member 110 in its uppermost or port-closing position after the overshot 25 has been removed.

Conversely, whenever the running overshot 25 is reengaged over the fishing neck 26, the resilient fingers 116 of the overshot 25 will engage the top of the valve memher 110 and shift it downwardly to reopen the equalizing ports 109. Serrated teeth 122 are provided around the lower end of the overshot 25 for cutting through any debris that may have fallen on top of the bridge plug 24 while it was set in place.

Accordingly, whenever the mandrel 31 has been rotated sufliciently to set the packing means 30 into sealing engagement with the casing, the overshot 25 will then be disengaged from the fishing neck 26 and the tool 20 moved on up the well bore. As has been already explained, removal of the overshot 25 will shift the slidable valve member 110 upwardly and close the equalizing ports 9 109 so as to completely block fluid communication from one side of the bridge plug 24 to the other.

Whenever it is desired to release and retrieve the bridge plug 24, the overshot 25 is dropped over and re-engaged with the fishing neck 26. Once the overshot 25 reaches its engaging position, J-pins 108 will re-enter the upper end of the J-slots 107 on the fishing neck 26. As the J- pins 108 re-enter the closed portion of the slots, the slidable valve member 110 is again shifted downwardly to re-open the equalizing ports 109. Thus, pressure will be equalized across the bridge plug 24 which will enable it to be retracted and easily removed.

Retraction of the bridge plug 24 is simply done by rotating the mandrel 31 to the left, which action returns the tubular sleeve member 28 upwardly along the threads 35 in the housing 29, thereby relaxing the packing means 30 and allowing it to reassume its normal configuration.

It will also be appreciated that whenever the tubular sleeve 28 has been screwed back upwardly to its initial starting position, the mandrel 31 will be angularly realigned relative to the housing 29 and the inwardly projecting locking lug member 43 will again be substantially aligned with the longitudinal groove portion 29 of the T-groove 47 in the outer surface of the mandrel 31. Thus, if the lug 43 has not already relatched, the operator needs only to shift the tubing 21 and mandrel 31 upwardly and downwardly slightly until the lug end 46 re-enters the T- groove 47. The operator cannot observe the operation of this lug, of course, but inasmuch as the anchor 34 remains engaged with the casing so long as the mandrel 31 is not locked, the bridge plug 24 cannot be moved until the lug end 46 has re-entered the T-groove 47.

As an added feature, it will be noted in FIG. 2E that should annular spacer member 96 be reversed end-forend, the compensating piston 92 will be shifted upwardly a substantial distance. It will be understood, of course, that such reversal will accordingly displace more fluid into the hydraulic system proper, which will naturally inflate the elastomeric sleeve 59 a corresponding amount. Accordingly, by properly proportioning the dimensions of the hydraulic system, one particular model of the bridge plug 24 may be successfully operated in various sizes of casing having widely differing internal diameters. By pre-inflating the elastomeric sleeve 59 in this manner,

the casing-engaging members 60, 61 Will consequently be moved closer to the casing before the mandrel 31 is actuated. Thus, it is made certain that the members 60, 61 will engage the casing before the mandrel 31 has been shifted its full extent thereby ensuring that additional longitudinal shifting of the mandrel will serve to press the members more tightly against the casing.

Turning now to FIG. 8, an alternate embodiment 24' of the bridge plug of the present invention is partially shown. This alternate embodiment is substantially the same as that already described with the sole exception that the drag blocks 33 have been eliminated and the friction anchor 34 itself is utilized to develop the initial drag for holding the housing 29 relatively fixed to the casing as the bridge plug 24' is being set.

In this modification, the annular spacer member 96 (FIG. 2B) is no longer required and spring 95 is replaced with a substantially heavier spring 95 (FIG. 9). This heavier spring 95' is made sufficiently strong that it will bias the compensating piston 92' upwardly to develop and maintain a slight pressure within the hydraulic system. The hydraulic pressure so developed is sufficient to maintain the casing-engaging members 60, 61 against the casing. Thus, the anchor 34 will also serve to initially restrain the housing 29'from turning in the same manner as the drag blocks 33 did in the previously described embodiment.

It will be understood, of course, that since the casingengaging members are maintained in engagement with the casing, it is not necessary to bias these members 60, 61 inwardly. Thus, the arcuate springs 71, 72 are not required in this alternate embodiment as shown in FIG. 8. During operation of the bridge plug 24, whenever the mandrel 31 is freed from the releasable latch means 32 and shifts, the reduced diameter portion 98 around the periphery of the mandrel 31 is moved out of alignment with O-ring 88 which allows the lower slidable piston member 80 to be fluidly sealed around the index mandrel as has been previously described. Shifting of the mandrel in either direction will develop a still greater hydraulic pressure to press the anchor 34 into anchoring engagement with a force proportional to the pressure differential across the bridge plug 24'.

Referring now to FIG. 9, a partial View is shown of an alternate embodiment 24" of the bridge plug of the present invention. In this alternate embodiment 24", the latch means 32 and the threads 35 previously described in conjunction with the embodiments of FIGS. 2 and 8 have been modified to allow the tubular sleeve 28 to make at least a full revolution to fore-shorten the packing means 30. Aside from these modifications to be described, the bridge plug 24 is arranged as already described either with the drag blocks 33 (FIG. 2) or without them (FIG. 8).

In FIG. 9, the lower portion of the packing means 30 is seen resting upon the upper end of the housing 29". In the same manner as previously described, the tubular sleeve member 28 has its lower end telescopically arranged within and has threads 123 threadedly engaged with internal right-hand threads 35" around the upper end of the housing 29". 28" has an annular groove receiving an O-ring 125 for fluidly sealing the extension relative to the housing 29".

In the same manner as previously described, the mandrel 31" is telescoped through the tubular sleeve 28 and co-rotatively secured thereto by longitudinal splines (not shown) cooperatively and slidably received within elon-' gated longitudinal spline grooves (not shown). The mandrel 31" is selectively secured against longitudinal shifting by a releasable latching means 32". This latching means 32" normally prevents the index mandrel 31" from either rotating or shifting longitudinally with respect to the housing 29". Upon application of righthand torque to the mandrel 31", the mandrel is initially secured against rotation relative to the housing 29" until the torque reaches a predetermined magnitude. When the torque reaches this pre-determined level, the mandrel 31" is then freed for both rotation and longitudinal shifting with respect to the housing 29".

As seen in FIGS. 9 and 10, the latching means 32" is comprised of a clutch mechanism 126 which releasably secures the housing 29 to an annular member 127 having inwardly projecting lugs 128 cooperatively received in T-shaped grooves 47" formed in opposite sides of the mandrel 31". Each of these grooves 47" are similar to that already described and illustrated in FIG. 3 with the exception that instead of diverging outwardly until its bottom merges into the outer surface of the mandrel, the branch portion 50 of the groove 47" opens into an enclosed, greatly elongated, longitudinal groove portion 129. The long groove portion 129 is parallel to the shorter groove portion 49" and extends above and below the shorter groove portion. All groove portions 49", 50" and 129 are of equal depth so it will be appreciated that the lug members 128 will always be confined within one of these groove portions. Thus, when the mandrel 31 is secured, the lugs 128 will be within their respective shorter groove portions 49"; and, when the mandrel is released, the lugs 128 will be within their respective great ly elongated groove portions 129. r

The clutch mechanism 126 is comprised of alternately disposed, flat, annular clutch plates 130, 131 urged into engagement with one another by a clutch spring 132. One set of the clutch plates is secured against rotation relative to the housing 29" by longitudinal housing splines 133 which are cooperatively received in radial notches An extension 124 of the sleeve or grooves on the outer edge of these plates 130. The other set 131 of the clutch plates is secured in a similar manner to the outside of the annular member 127 by longitudinal splines 134 along the outer surface of that member.

Thus, depending upon the strength of the clutch spring 132, the contiguous plates 130, 131 will be frictionally secured one to the other until sutficient torque is applied through the mandrel 31" to overcome the frictional force. Then, the clutch plates 130 secured to the housing 29" will remain stationary as the clutch plates 131 secured to the annular member 127 slidably rotate therebetween.

Accordingly, when the mandrel 31" is first rotated, the frictionally engaged clutch plates 130, 131 will initially restrain the annular member 127. This will allow the mandrel 31" to rotate the groove portions 49" away from the momentarily-fixed lugs 128 and rotate the greatly elongated groove portions 129 into alignment with the lugs. Once the lugs 128 engage the straight sides of groove portions 129, the mandrel 31" will, of course, be momentarily halted since the annular member 127 is still secured by the clutch plates 130, 131 to the fixed housing 29". Continued application of torque to the mandrel 31", however, will soon increase the torsional force to a magnitude sufiicient to overcome the frictional restraint provided by the clutch plates 130, 131. At this time, the annular member 127 begins to rotate with respect to the housing 29" and the mandrel 31" is now free to shift longitudinally in either direction with respect to both the housing 29" and annular member 127.

Once the mandrel 31" begins to rotate to the right, the tubular sleeve member 28" begins rotating (because of the splines co-rotatively securing it to the mandrel) downwardly along threads 35" to begin foreshortening the packing means 30. It will be realized, however, that now in contrast to the other two embodiments, the mandrel may rotate a full turn or more without becoming re-secured. Thus, where it is necessary to displace the packing means 30 outwardly an extra amount, the mandrel 31" may be rotated several turns to ensure that the packing means i fully displaced.

As an added feature, a slidable annular piston 135 is placed in an annular clearance space 136 in the upper end of the housing 29" and fluidly sealed by O-rings 137, 138 to the housing and tubular sleeve 28". A port 139 through the housing 2?" above the piston 135 allows the pressure of fluids in the well bore beneath the packing means 30 to act on the upper face of the piston. A fluid passage 140 in the housing 29" connects the annular clearance space 141 around the threads 35" to the space 142 enclosing the clutch plates 130, 131. A sealed bydraulic chamber is provided between the piston 135 by an O-ring 143 which fluidly seals the annular member 127 to the housing 29". This sealed chamber is filled with a suitable hydraulic fluid to lubricate the threads 35", 123 as well as the clutch plates 136, 131. An O-ring 144 around the upper end of the annular member 127 as well as the O-ring 125 around the sleeve extension 124 fluidly seal the intermediate portions of the sealed hydraulic chamber. Thus, it will be realized that when the packing means 30 is sealingly engaged with a casing, any pressure acting upwardly on the bridge plug 24" that might tend to jam the threads 35", 123 will be substantially counterbalanced since the balancing piston 135 will develop the same pressure in the fluid-filled, sealed, bydraulic chamber between the piston and O-ring 143.

An additional feature is provided by disposing an O-ring 145 loosely around the sleeve 28" above its threads 123. Whenever the sleeve 28" is returned to its upper-most position, it will be brought to rest by the O-ring 145 engaging an inwardly projecting stop or shoulder 146. A passage 147 through the shoulder 146 ensures free fluid communication between the piston 135 and remainder of the sealed hydraulic chamber.

Except as already discussed, the bridge plug 24", of

course, operates in the same manner as those shown in FIGS. 2 and 8. It will be appreciated, of course, that when the packing means 30 is to be retracted, the mandrel 31" is torqued to the left which returns the sleeve 28" back up threads 35". Then, by holding the lefthand torque, the lugs 128 will re-enter the short groove portions 49 whenever the mandrel 31 is shifted to realign the lugs with groove portions 50".

Accordingly, it will be appreciated that each of the bridge plugs described herein provide new and amproved packing apparatus having hydraulically-actuated Wallengaging members which are pressed into anchoring engagement by a longitudinally directed force on the shit-t able mandrel. It will be realized, of course, that such a longitudinally directed force may be imposed either by a pressure differential acting from either above or below the bridge plug or by engaging the mandrel with a member lowered into the well and manipulating the mandrel in either longitudinal direction.

Moreover, the force directed against the shiftable mandrel will be proportionately related to the anchoring force securing the bridge plug within the well. It will be realized as well that the developed anchoring force will be independent of the force applied to foreshorten the packing means and displace it into sealing engagement.

Furthermore, it has been shown how each of the bridge plugs employ conventional annular packing means which are sealingly engaged by a rotative motion.

While particular embodiments of the present invention have been shown and described, it is apparent that changes and modifications may be made Without departing from this invention in its broader aspects and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of this invention.

What is claimed is:

1. A well packer sized and adapted for reception in a well bore for packing-oil the well bore, comprising: a housing; a rotatable tubular member threadedly engaged with said housing, said tubular member havinga fixed shoulder longitudinally spaced from said housing; packing means mounted around said tubular member intermediate said shoulder and said housing, said packing means being adapted for expansion into sealing engagement with the well bore upon rotation of said tubular member; anchoring means for securing said well packer within the well bore including outwardly-extendible wallen-gaging means operatively mounted on said housing; a body member slidably disposed within the bore of said tubular member and arranged to shift longitudinally therein; and hydraulic means responsive to shitting of said body member for pressing said wall-engaging means into anchoring engagement to anchor said well packer with a force proportionately related to the distance said body member shifts.

2. A well packer sized and adapted for reception in a well bore for packing-01f the well bore, comprising: a housing; a rotatable tubular member threadedly engaged with said housing, said tubular member having a fixed shoulder longitudinally spaced from said housing; packing means mounted around said tubular member intermediate said shoulder and said housing, said packing means being adapted for expansion into sealing engagement with the well bore upon rotation of said tubular member; anchoring means for securing said well packer Within the well bore including outwardly-extendible wallengaging means operatively mounted on said housing and fluidly sealed relative thereto to provide a fluid-tight space therebetween, said wall-engaging means being arranged and adapted to extend upon application of hydraulic pressure in said fluid-tight space; a body member slidably disposed within the bore of said tubular member and arranged to shift longitudinally therein; and hydraulic means responsive to shifting of said body member for applying a hydraulic pressure in said fluid-tight space 13 to press said wall-engaging means into anchoring engagement and anchor said well packer with a force proportionately related to the distance said body member shifts.

3. A well packer sized and adapted for reception in a well bore for packing-off the well bore, comprising: a housing having a central longitudinal bore; a rotatable tubular member disposed in said housing bore and threadly engaged with said housing, said tubular member having a fixed shoulder longitudinally spaced from said housing; packing means mounted around said tubular member intermediate said shoulder and said housing, said packing means being adapted for expansion into sealing engagement with the well bore upon rotation of said tubular member; anchoring means for securing said well packer within the Well bore including outwardly-extendible wallengaging means operatively mounted on said housing and fluidly sealed relative thereto to provide a fluid-tight space therebetween, said wall-engaging means being arranged and adapted to extend upon application of hydraulic pressure in said fluid-tight space; a body member slidably disposed Within said tubular member and housing bore and operatively arranged to shift longitudinally therein in response to a pressure differential between fluids in the well bore above and below said well packer; and hydraulic means responsive to shifting of said body member for applying a hydraulic pressure in said fluid-tight space to press said wall-engaging means into anchoring engagement and anchor said well packer with a force proportionately related to the pressure differential.

4. A well packer sized and adapted for reception in a well bore for packing-off the Well bore, comprising: a housing having a central longitudinal bore; a rotatable tubular member threadedly engaged with said housing, said tubular member haxing a fixed shoulder longitudinally spaced from said housing; packing means mounted around said tubular member intermediate said shoulder and said housing, said packing means being adapted for expansion into sealing engagement with the Well bore upon rotation of said tubular member; anchoring means for securing said well packer within the well bore including outWardly-extendible wall-engaging means mounted on said housing and fluidly sealed relative thereto to provide a fluid-tight space therebetween, said wall-engaging means being adapted to extend upon application of hydraulic pressure in said fluid-tight space and press said wall-engaging means into anchoring engagement with the well bore; a rotatable body member slidably disposed Within said tubular member and housing and arranged to shift longitudinally therein in response to fluid pressure in a well bore; and hydraulic means responsive to shifting of said body member for developing a hydraulic pressure to extend said wall-engaging means including a piston member slidably disposed in said housing bore and adapted to be engaged by said body member and advanced along said bore thereby whenever said body member shifts in one direction, first means fluidly sealing said housing bore at a point longitudinally spaced from said piston member in said one direction, second means fluidly sealing said piston member for providing a fluid-tight chamber in said housing bore intermediate said piston member and said longitudinally displaced point, and passage means providing fluid communication between said fluid-tight chamber and said fluid-tight space, said fluid-tight chamber and space being filled with fluid.

5. A well packer sized and adapted for reception in a well bore for packing-off the well bore, comprising: a housing having a central longitudinal bore; a rotatable tubular member threadedly engaged with said housing, said tubular member having a flange longitudinally spaced from said housing; packing means mounted around said tubular member intermediate said flange and said housing, said packing means being adapted for expansion into sealing engagement with the well bore upon rotation of said tubular member; anchoring means for securing said well packer within the well bore including an inflatable elastomeric sleeve sealingly mounted around said housing to provide a fluid-tight space therebetween and wall-engaging means mounted around said elastomeric sleeve, said elastomeric sleeve being adapted to expand upon application of hydraulic pressure in said fluid-tight space and press said Wall-engaging means into anchoring engagement with the well bore; a rotatable body member slidably disposed within said tubular member and housing and arranged to shift longitudinally therein in response to fluid pressure in a well bore; hydraulic means responsive to shifting of said body member for developing a hydraulic pressure to inflate said elastomeric sleeve including a piston member slidably disposed in said housing bore and adapted to be engaged by said body member and advanced along said bore thereby whenever said body member shifts in one direction, first means fluidly sealing said housing bore at a point longitudinally spaced from said piston member in said one direction, second means fluidly sealing said piston member for providing a fluid-tight chamber in said housing bore intermediate said piston member and said longitudinally displaced point, and passage means providing fluid communication between said fluid-tight chamber and said fluid-tight space, said fluid-tight chamber and space being filled with fluid; and releasable latching means securing said body member against longitudinal shifting, said latching means being responsive to rotation of said tubular member to free said body member for longitudinal shifting and responsive to rotation of said tubular member in the opposite direction to resecure said body member against longitudinal shifting.

6. A well packer sized and adapted for reception in a well bore for packing-off the well bore, comprising: a housing having a central longitudinal bore; a rotatable tubular member threadedly engaged with said housing, said tubular member having a fixed shoulder longitudinally spaced from said housing; packing means mounted around said tubular member intermediate said shoulder and said housing, said packing means being adapted for expansion into sealing engagement with the well bore upon rotation of said tubular member; first anchoring means for securing said housing against rotation relative to the well bore including first wall-engaging means operatively mounted around said housing and spring means for biasing said first wall-engaging means into engagement with the well bore; second anchoring means for selectively securing said well packer against longitudinal displacement within the well bore including an inflatable elastomeric sleeve sealingly mounted around said housing to provide a fluid-tight space therebetween and second wall-engaging means mounted around said elastomeric sleeve, said elastomeric sleeve being adapted to expand upon application of hydraulic pressure in said fluid-tight space to press said second wallengaging means into anchoring engagement with the well bore; a rotatable body member slidably disposed within said tubular member and housing and arranged to shift longitudinally therein in response to fluid pressure in a well bore; and hydraulic means responsive to shifting of said body member for develop-ing a hydraulic pressure to inflate said elastomeric sleeve including a piston member slidably disposed in said housing bore and adapted to be engaged by said body member and advanced along said bore thereby whenever said body member shifts in one direction, first means fluidly sealing said housing bore at a point longitudinally spaced from said piston member in said one direction, second means fluidly sealing said piston member for providing a fluid-tight chamber in said housing bore intermediate said piston member and said longitudinally displaced point, and passage means providing fluid communication between said fluid-tight chamber and said fluid-tight space, said fluid-tight chamber and space being filled with fluid.

7. A well packer sized and adapted for reception in a well bore for packing-off the Well bore, comprising: a housing having a central longitudinal bore; a rotatable tubular member threadedly engaged with said housing, said tubular member having a fixed shoulder longitudinally spaced from said housing; packing means mounted around said tubular member intermediate said shoulder and said housing, said packing means being adapted for expansion into sealing engagement with the well bore upon rotation of said tubular member; anchoring means for securing said well packer within the Well bore including an inflatable elastomeric sleeve sealingly mounted around said housing to provide a fluid-tight space therebetween and wall-engaging means mounted around said elastomeric sleeve, said elastomeric sleeve being adapted to expand upon application of hydraulic pressure in said fluid-tight space and press said Wall-engaging means into anchoring engagement with the well bore; a rotatable body member slidably disposed within said tubular member and housing and arranged to shift longitudinally therein in response to fluid pressure in a Well bore; hydraulic means responsive to shifting of said body member for developing a hydraulic pressure to inflate said elastomeric sleeve including a piston member slidably disposed in said housing bore and adapted to be engaged by said body member and advanced along said bore thereby whenever said body member shifts in one direction, first means fluidly sealing said housing bore at a point longitudinally spaced from said piston member in one direction, second means fluidly sealing said piston member for providing a fluid-tight chamber in said housing bore intermediate said piston member and said longitudinally displaced point, and passage means providing fluid communication between said fluid-tight chamber and said fluid-tight space, said fluidtight chamber and space being filled with fluid; and means for maintaining pressure in said fluid-tight chamber and space to inflate said elastomeric sleeve for securing said housing against rotation relative to said body member.

8. A well packer sized and adapted for reception in a well bore for packing-off the well bore, comprising: a housing having a central longitudinal bore; a rotatable tubular member threadedly engaged with said housing, said tubular member having a fixed shoulder longitudinally spaced from said housing; packing means mounted around said tubular member intermediate said shoulder and said housing, said packing means being adapted for expansion into sealing engagement with the Well bore upon rotation of said tubular member; anchoring means for securing said well packer Within the well bore including an inflatable elastomeric sleeve sealingly mounted around said housing to provide a fluid-tight space therebetween and wall-engaging means mounted around said elastomeric sleeve, said elastomeric sleeve being adapted to expand upon application of hydraulic pressure in said fluid-tight space and press said wall-engaging means into anchoring engagement with the Well bore; a rotatable body member slidably disposed within said tubular member and housing and arranged to shift longitudinally therein in response to fluid pressure in a Well bore; hydraulic means responsive to shifting of said body member for developing a hydraulic pressure to inflate said elastomeric sleeve including first and second piston members slidably disposed in said housing bore and spaced apart, means fluidly sealing said piston members providing a fluid-tight chamber in said housing bore between said piston members, passage means providing fluid communication between said fluid-tight chamber and said fluid-tight space, said fluid-tight chamber and space being filled with fluid, first means for advancing said first piston member toward said second piston member whenever said body member shifts in one direction and second means for advancing said second piston member toward said first piston member whenever said body member shifts in the opposite direction.

9. A well packer sized and adapted for reception in a well bore for packing-cit the well bore, comprising: a housing having a central longitudinal bore; a rotatable tubular member threadedly engaged with said housing,

said tubular member having a fixed shoulder longitudinally spaced from said housing; packing means mounted around said tubular member intermediate said shoulder and said housing, said packing means being adapted for expansion into sealing engagement with the well bore upon rotation of said tubular member; anchoring means for securing said well packer within the well bore including an inflatable elastomeric sleeve sealingly mounted around said housing to provide a fluid-tight space therebetween and wall-engaging means mounted around said elastomeric sleeve, said elastomeric sleeve being adapted to expand upon application of hydraulic pressure in said fluid-tight space and press said wall-engaging means into anchoring engagement with the Well bore; a rotatable body member slidably disposed Within said tubular member and housing and arranged to shift longitudinally therein in response to fluid pressure in a Well bore; hydraulic means responsive to shifting of said body member for developing a hydraulic pressure to inflate said elastomeric sleeve including first and second piston members slidably disposed in said housing bore and spaced apart, means fluidly sealing said piston member providing a fluid-tight chamber in said housing bore between said piston members, passage means providing fluid communication between said fluid-tight chamber and said fluidtight space, said fluid-tight chamber and space being filled with fluid, first means for advancing said first piston member toward said second piston member whenever said body member shifts in one direction and second means for advancing said second piston member toward said first piston member whenever said body member shifts in the opposite direction; means for maintaining pressure in said fluid-tight chamber and space to inflate said elastomeric sleeve for securing said housing against rotation relative to said body member; and releasable latching means securing said body member against longitudinal shifting, said latching means being responsive to rotation of said body member for expanding said packing means to free said body member for longitudinal shifting.

10. A well packer sized and adapted for reception in a well bore for packing-cit the well bore, comprising: a housing having a central longitudinal bore; a rotatable tubular member threadedly engaged with said housing, said tubular member having a fixed shoulder longitudinally spaced from said housing; packing means mounted around said tubular member intermediate said shoulder and said housing, said packing means being adapted for expansion into sealing engagement with the Well bore upon rotation of said tubular member; first anchoring means for securing said housing against rotation relative to the Well bore including first wall-engaging means operatively mounted around said housing and spring means for biasing said first Wall-engaging means into engagement with the Well bore; second anchoring means for selectively securing said well packer against longitudinal displacement within the well bore including an inflatable elastomeric sleeve sealingly mounted around said housing to provide a fluid-tight space therebetween and second wall-engaging means mounted around said elastomeric sleeve, said elastomeric sleeve being adapted to expand upon application of hydraulic pressure in said fluid-tight space to press said second wall-engaging means into anchoring engagement with the well bore; a rotatable body'member slidably disposed within said tubular member and housing and arranged to shift longitudinally therein in response to fluid pressure in a well bore; hydraulic means responsive to shifting of said body member for developing a hydraulic pressure to inflate said elastomeric sleeve including first and second piston members slidably disposed in said housing bore and spaced apart, means fluidly sealing said piston members providing a fluid-tight chamber in said housing bore between said piston members, passage means providing fluid communication between said fluid-tight chamber and said fluid-tight space, said fluid-tight chamber and space being filled with fluid, first means for advancing said first piston member toward said second piston member whenever said body member shifts in one direction and second means for advancing said second piston member toward said first piston member whenever said body member shifts in the opposite direction; and releasable latching means securing said body member against longitudinal shifting, said latching means being responsive to rotation of said body member for expanding said packing means to free said body member for longitudinal shifting.

11. A well packer sized and adapted for reception in a well bore for packing-off the well bore, comprising: a housing having a central longitudinal bore; a rotatable tubular member threadedly engaged with said housing, said tubular member having a fixed shoulder longitudinally spaced from said housing; packing means mounted around said tubular member intermediate said shoulder and said housing, said packing means being adapted for expansion into sealing engagement with the well bore upon rotation of said tubular member; first anchoring means for securing said housing against rotation relative to the well bore including first wall-engaging means operatively mounted around said housing and spring means for biasing said first wall-engaging means into engagement with the well bore; second anchoring means for selectively securing said well packer against longitudinal displacement within the well bore including an inflatable elastomeric sleeve sealingly mounted around said housing to provide a fluid-tight space therebetween and second wall-engaging means mounted around said elastomeric sleeve, said elastomeric sleeve being adapted to expand upon application of hydraulic pressure in said fluid-tight space to press said second wall-engaging means into anchoring engagement with the well bore; a rotatable body member slidably disposed within said tubular member and housing bore and arranged to shift longitudinally therein in response to fluid pressure in a well bore; hydraulic means responsive to shifting of said body member for developing a hydraulic pressure to inflate said elastomeric sleeve including first and second annular piston members slidably disposed around said body member and slidably received within said housing bore, said piston members being spaced apart, means fluidly sealing said piston members providing a fluid-tight chamber in said housing bore between said piston members, passage means providing fluid communication between said fluid-tight chamber and said fluid-tight space, said fluid-tight chamber and space being filled with fluid, stop means limiting retrogression of said piston members, biasing means normally urging said piston members against said stop means, first means on said body member for advancing said first piston member toward said second piston member whenever said body member shifts in one direction and second means on said body member for advancing said second piston member toward said first piston member whenever said body member shifts in the opposite direction; and releasable latching means securing said body member against longitudinal shifting, said latching means being responsive to rotation of said body member for expanding said packing means to free said body member for longitudinal shifting and responsive to rotation of said body member in the opposite direction to resecure said body member against longitudinal shifting.

12. A well packer sized and adapted for reception in a well bore for packing-off the well bore, comprising: a housing having a central longitudinal bore; a rotatable tubular member threadedly engaged with said housing, said tubular member having a fixed shoulder longitudinally spaced from said housing; packing means mounted around said tubular member intermediate said shoulder and said housing, said packing means being adapted for expansion into sealing engagement with the well bore upon rotation of said tubular member; anchoring means for securing said well packer within the well bore including an inflatable elastomeric sleeve sealingly mounted around said housing to provide a fluid-tight space therebetween and wall-engaging means mounted around said elastomeric sleeve, said elastomeric sleeve being adapted to expand upon application of hydraulic pressure in said fluid-tight space and press said wall-engaging means into anchoring engagement with the well bore; a rotatable body member slidably disposed within said tubular member and housing bore and arranged to shift longitudinally therein in response to fluid pressure in a well bore; hydraulic means responsive to shifting of said body member for developing a hydraulic pressure to inflate said elastomeric sleeve including first and second annular piston members slidably disposed around said body member and slidably received within said housing bore, said piston members being spaced apart, means fluidly sealing said piston members providing a fluid-tight chamber in said housing bore between said piston members, passage means providing fluid communication between said fluid-tight chamber and said fluid-tight space, said fluid-tight chamber and space being filled with fluid, stop means limiting retrogression of said piston members, biasing means normally urging said piston members against said stop means, first means on said body member for advancing said first piston member toward said second piston member whenever said body member shifts in one direction and second means on said body member for advancing said second piston member toward said first piston member whenever said body member shifts in the opposite direction; and releasable latching means securing said body member against longitudinal shifting, said latching means being responsive to rotation of said body member for expanding said packing means to free said body member for longitudinal shifting.

13. A well packer sized and adapted for reception in a well bore for packing-off the well bore, comprising: a housing having a central longitudinal bore; a rotatable tubular member threadedly engaged with said housing, said tubular member having a fixed shoulder longitudinally spaced from said housing; packing means mounted around said tubular member intermediate said shoulder and said housing, said packing means being adapted for expansion into sealing engagement with the well bore upon rotation of said tubular member; anchoring means for securing said well packer within the well bore including an inflatable elastomeric sleeve sealingly mounted around said housing to provide a fluid-tight space therebetween and wallengaging means mounted around said elastomeric sleeve, said elastomeric sleeve being adapted to expand upon application of hydraulic pressure in said fluid-tight space to press said wall-engaging means into anchoring engagement with the well bore; a rotatable body member slidably disposed within said tubular member and housing bore and arranged to shift longitudinally therein in response to fluid pressure in a well bore; hydraulic means responsive to shifting of said body member for developing a hydraulic pressure to inflate said elastomeric sleeve including first and second annular piston members slidably disposed around said body member and slidably received within said housing bore, said piston members being spaced apart, means fluidly sealing said piston members providing a fluid-tight chamber in said housing bore between said .piston members, passage means providing fluid communication between said fluid-tight chamber and said fluid-tight space, said fluid-tight chamber and space being filled with fluid, stop means limiting retrogression of said piston members, biasing means normally urging said piston members against said stop means, first means on said body member for advancing said first piston member toward said second piston member whenever said body member shifts in one direction and second means on said body member for advancing said second piston member toward said first piston member whenever said body member shifts in the opposite direction; means for maintaining pressure in said fluid-tight chamber and space for inflating said elastomeric sleeve to press said wall-engaging means into engagement with the well bore and secure said housing against rotation relative to said body member; and releasable latching means securing said body member against longitudinal shifting, said latching means being responsive to rotation of said body member for expanding said packing means to free said body member for longitudinal shifting and responsive to rotation of said body member in the opposite direction to resecure said body member against longitudinal shifting.

14. A well packer sized and adapted for reception in a Well bore for packing-cit the well bore, comprising: a housing having a central longitudinal bore; a rotatable tubular member threadedly engaged with said housing, said tubular member having a fixed shoulder longitudinally spaced from said housing; packing means mounted around said tubular member intermediate said shoulder and said housing, said packing means being adapted for expansion into sealing engagement with the well bore upon rotation of said tubular member; anchoring means for securing said well packer relative to the well bore including an infiatable elastomeric sleeve sealingly mounted around said housing to provide a fluid-tight space therebetween and Wall-engaging means mounted around said elastorneric sleeve, said elastomeric sleeve being adapted to inflate upon application of hydraulic pressure in said fluid-tight space to press said wall-engaging means into engagement with the well bore; actuating means for rotating said tubular member to expand said packing means into sealing engagement with the well bore including a rotatable body member slida'bly disposed within said tubular member and housing bore and arranged to shift therein in response to fluid pressure in a well bore; means co-rotatively securing said tubular member to said body member and limiting longitudinal shifting of said body member; hydraulic means for inflating said elastomeric sleeve to press said wall-engaging means into engagement with the Well bore with sulficient force to secure said housing against rotation relative to said body member including first means fluidly sealing-off a portion of said housing bore, a piston member slidably disposed in said housing bore and longitudinally displaced from said first sealing means, biasing means normally urging said piston member toward said first sealing means, second means fluidly sealing said piston member providing a fluidtight chamber in said housing bore intermediate said first sealing means and piston member, and conduit means providing fluid communication between said fluid-tight chamber and said fluid-tight space, said fluid-tight chamber and space being filled with fluid; and means for inflating said elastomeric sleeve to press said wall-engaging means into anchoring engagement with the well bore with a force proportional to fluid pressure in the well bore including means on said body member adapted to engage and advance said piston member whenever said body member is shifted toward said first sealing means to develop a hydraulic pressure in said fluid-filled space.

15. A well packer sized and adapted for reception in a well bore for packing-01f the well bore, comprising: a housing; a rotatable member threadedly engaged with said housing, said rotatable member having a fixed shoulder longitudinally spaced from said housing; packing means mounted around said rotatable member intermediate said shoulder and said housing, said packing means being adapted for expansion into sealing engagement with the well bore upon rotation of said rotatable member; anchoring means for securing said well packer Within the Well bore including extendible wall-engaging means operatively mounted on said housing; and means responsive to torque of a predetermined magnitude for releasably connecting said rotatable member to said housing.

16. A well packer sized and adapted for reception in a well bore for packing-off the well bore, comprising: a housing; a rotatable member threadedly engaged with said housing, said rotatable member having a fixed shoulder longitudinally spaced from said housing; packing means mounted around said rotatable member intermediate said shoulder and said housing, said packing means being adapted for expansion into sealing engagement with the well bore upon rotation of said rotatable member; anchoring means for securing said well packer within the well bore including extendible wall-engaging means operatively mounted on said housing; and means responsive to torque of a predetermined magnitude for releasably connecting said rotatable member to said housing including first clutch means secured to said housing, second clutch means operatively engaged with said first clutch means and connected to said rotatable member and means biasing said clutch means into engagement with one another.

17. A well packer sized and adapted for reception in a well bore for packing-off the well bore, comprising: a housing; a rotatable member threadedly engaged with said housing, said rotatable member having a fixed shoulder longitudinally spaced from said housing; packing means mounted around said rotatable member intermediate said shoulder and said housing, said packing means being adapted for expansion into sealing engagement with the well bore upon rotation of said rotatable member; anchoring means for securing said well packer within the well bore including outward-extendible wall-engaging means operatively mounted on said housing; means responsive to torque of a predetermined magnitude for releasably connecting said rotatable member to said housing; and hydraulic means operable upon release of said rotatable member and responsive to a pressure differential across said well packer of well fluids above and below said packer for pressing said wall-engaging means into anchoring engagement with a force proportionately related to this pressure differential.

18. A well packer sized and adapted for reception in a well bore for packing-off the Well bore, comprising: a housing having a central longitudinal bore; a rotatable tubular member threadedly engaged with said housing, said rotatable member having a fixed shoulder longitudinally spaced from said housing; a packing means mounted around said rotatable member intermediate said shoulder and said housing, said packing means being adapted for expansion into sealing engagement with the well bore upon rotation of said rotatable member; a body member slidably disposed in said rotatable member and co-rotatively secured thereto and arranged to shift longitudinally therein; anchoring means for securing said well packer within the well bore including outwardly-extendible wall-engaging means operatively mounted on said housing; means responsive to torque of a predetermined magnitude for releasably coupling said body member to said housing; and hydraulic means operable upon release of said body member and responsive to shifting of said body member for pressing said wall-engaging means into anchoring engagement to anchor said well packer with a force proportionately related to the distance said body member shifts.

19. A well packer sized and adapted for reception in a well bore for packingpfl the well bore, comprising: a housing having a central longitudinal bore; a rotatable tubular member threadedly engaged with said housing, said rotatable member having a fixed shoulder longitudinally spaced from said housing; packing means mounted around said rotatable member intermediate said shoulder and said housing, said packing means being adapted for expansion into sealing engagement with the well bore upon rotation of said rotatable member; a body member slidably disposed in said rotatable member and co-rotatively secured thereto and arranged to shift longitudinally therein; anchoring means for securing said well packer within the well bore including outwardly-extendible wall-engaging means operatively mounted on said housing and fluidly sealed relative thereto to provide a fluidtight space therebetween, said wall-engaging means being adapted for extension into engagement with the Well bore upon application of hydraulic pressure in said fluid-tight space; means responsive to torque of a predetermined magnitude for releasably coupling said body member to said housing; and hydraulic means operable upon release of said body member and responsive to shifting of said body member for applying a hydraulic pressure into said fluid-tight space to press said wall-engaging means into anchoring engagement to anchor said well packer with a force proportionately related to the distance said body member shifts.

20. A well packer sized and adapted for reception in a well bore for packing-off the well bore, comprising: a housing having a central longitudinal bore; a rotatable tubular member threadedly engaged with said housing, said rotatable member having a fixed shoulder longitudinally spaced from said housing; packing means mounted around said rotatable member intermediate said shoulder and said housing, said packing means being adapted for expansion into sealing engagement with the well bore upon rotation of said rotatable member; a body member slidably disposed in said rotatable :member and co-rotatively secured thereto and arranged to shift longitudinally therein; anchoring means for securing said well packer within the well bore including outwardly-extendible wallengaging means operatively mounted on said housing and fluidly sealed relative thereto to provide a fluid-tight space therebetween, said wall-engaging means being adapted for extension into engagement with the well bore upon application of hydraulic pressure in said fluid-tight space; means responsive to torque of a predetermined magnitude for releasably coupling said body member to said housing including first clutch means secured to said housing, second clutch means operatively engaged with said first clutch means and connected to said body member and means biasing said clutch means into engagement with one another; and hydraulic means operable upon release of said body member and responsive to shifting of said body member for applying a hydraulic pressure into said fluid-tight space to press said Wall-engaging means into anchoring engagement to anchor said Well packer with a force proportionately related to the distance said body member shifts.

21. A well packer sized and adapted for reception in a well bore for packing-off the Well bore, comprising: a housing having a central longitudinal bore; a rotatable tubular member threadedly engaged with said housing, said rotatable member having a fixed shoulder longi tudinally spaced from said housing; packing means mounted around said rotatable member intermediate said shoulder and said housing, said packing means being adapted for expansion into sealing engagement with the well bore upon rotation of said rotatable member; a body member slidably disposed in said rotatable member and co-rotatively secured thereto and arranged to shift longitudinally therein; anchoring means for securing said well packer within the well bore including outwardly-extendible wall-engaging means operatively mounted on said housing and fluidly sealed relative thereto to provide a fluid-tight space therebetween, said wall-engaging means being adapted for extension into engagement with the well bore upon application of hydraulic pressure in said fluid-tight space; means responsive to torque of a predetermined magnitude for releasably coupling said body member to said housing including stop means on said body member providing first and second longitudinally extending paths of different lengths angularly spaced-apart and joined together at one adjacent point, an annular member disposed around said body member and having an inwardlyprojecting member slidably received in said stop means, first clutch means in said housing bore secured to said housing, second clutch means operatively engaged with said first clutch means and secured to annular member and means biasing said clutch means into engagement with one another; and hydraulic means operable upon release of said body member and responsive to shifting of said body member for applying a hydraulic pressure into said fluid-tight space to press said wall-engaging means into anchoring engagement to anchor said well packer with a force proportionately related to the distance said body member shifts.

References Cited by the Examiner UNITED STATES PATENTS 2,638,168 5/1953 Parks 16612O 2,802,534 8/1957 Conrad 166196 X 2,825,410 3/1958 Brown 166-139 2,881,841 4/1959 Page 166-212 3,158,202 11/1964 Lewis et al. 166-121 3,171,490 3/1965 States 166139 X CHARLES E. OCONNELL, Primary Examiner.

D. H. BROWN, Assistant Examiner. 

15. A WELL PACKER SIZED AND ADAPTED FOR RECEPTION IN A WELL BORE FOR PACKING-OFF THE WELL BORE, COMPRISING: A HOUSING; A ROTATABLE MEMBER THREADEDLY ENGAGED WITH SAID HOUSING, SAID ROTATABLE MEMBER HAVING A FIXED SHOULDER LONGITUDINALLY SPACED FROM SAID HOUSING; PACKING MEANS MOUNTED AROUND SAID ROTATABLE MEMBER INTERMEDIATE SAID SHOULDER AND SAID HOUSING, SAID PACKING MEANS BEING ADAPTED FOR EXPANSION INTO SEALING ENGAGEMENT WITH THE WELL BORE UPON ROTATION OF SAID ROTATABLE MEMBER; ANCHORING MEANS FOR SECURING SAID WELL PACKER WITHIN THE WELL BORE INCLUDING EXTENDIBLE WALL-ENGAGING MEANS OPERATIVELY MOUNTED ON SAID HOUSING; AND MEANS RESPONSIVE TO TORQUE OF A PREDETERMINED MAGNITUDE FOR RELEASABLY CONNECTING SAID ROTATABLE MEMBER TO SAID HOUSING. 